1 00:00:03,840 --> 00:00:10,760 There is an epidemic sweeping the western world. It's an illness that takes many forms. 2 00:00:10,795 --> 00:00:16,245 It can make you sneeze and itch, or it could stop you breathing altogether. 3 00:00:16,280 --> 00:00:22,160 I've seen people who have gone from talking to me to collapse within a matter of minutes. 4 00:00:22,195 --> 00:00:27,477 50 years ago, it barely existed, yet in parts of the Western world 5 00:00:27,512 --> 00:00:32,760 it now affects one third of all adults and almost 40% of children. 6 00:00:32,795 --> 00:00:36,057 It is horrible, cos your eyes puff up and you can't see, and 7 00:00:36,092 --> 00:00:40,606 you get really panicky, and then you have panic attacks. 8 00:00:40,641 --> 00:00:44,380 This film will take you on a journey to uncover the secrets 9 00:00:44,415 --> 00:00:48,085 behind one of the biggest mysteries in modern medicine. 10 00:00:48,120 --> 00:00:55,520 I started to have to go on emergency oxygen because I stopped breathing. 11 00:00:55,555 --> 00:00:57,997 I'm scared for my children and my grandchildren 12 00:00:58,032 --> 00:01:00,440 and for everybody's children and grandchildren. 13 00:01:00,475 --> 00:01:03,645 I'm scared for the future of this planet. 14 00:01:03,680 --> 00:01:08,485 From the tropical islands of the Caribbean to the valleys of Wales, 15 00:01:08,520 --> 00:01:14,560 from the industrial heartlands of California to the most remote inhabited island in the world, 16 00:01:14,595 --> 00:01:20,440 Horizon attempts to find out why we are becoming allergic to our planet. 17 00:01:45,880 --> 00:01:52,560 We knew it was serious. I don't think... you appreciate 18 00:01:52,595 --> 00:01:57,765 how serious it could be, as you always think of it 19 00:01:57,800 --> 00:02:04,160 as a reaction that will cause a swelling or will cause vomiting. 20 00:02:04,195 --> 00:02:08,160 Mike and Sue Obatelli first realised their daughter Kate 21 00:02:08,195 --> 00:02:12,560 suffered from allergies when she was two years old. 22 00:02:12,595 --> 00:02:15,925 We were actually shopping in a supermarket 23 00:02:15,960 --> 00:02:19,205 and I gave her a taste of a fruit bar that I'd bought, 24 00:02:19,240 --> 00:02:24,960 a sticky fruit bar from the health food shop, and then immediately her mouth swelled, 25 00:02:24,995 --> 00:02:28,520 and we took her to the hospital because she couldn't even suck her dummy. 26 00:02:28,555 --> 00:02:34,600 Kate was subsequently diagnosed with a severe peanut allergy. 27 00:02:34,635 --> 00:02:38,197 Although Kate and her family were extremely vigilant, 28 00:02:38,232 --> 00:02:41,725 it proved impossible to avoid peanuts altogether. 29 00:02:41,760 --> 00:02:48,800 I got a phone call at 11 o'clock saying she was in an ambulance with no pulse, would we go over. 30 00:02:48,835 --> 00:02:51,937 We went to the hospital, they took us through, 31 00:02:51,972 --> 00:02:54,766 and there was about eight or nine people round her 32 00:02:54,801 --> 00:02:57,525 trying to save her life. And they just couldn't. 33 00:02:57,560 --> 00:03:02,525 And that's how quick it can happen and how serious it is. 34 00:03:02,560 --> 00:03:10,440 The slightest little bit, if you're so allergic, is a death sentence. 35 00:03:10,475 --> 00:03:13,685 Kate had ordered an Indian takeaway meal. 36 00:03:13,720 --> 00:03:16,880 Although she had specifically asked for no nuts, 37 00:03:16,915 --> 00:03:19,325 ground nuts had been added by mistake. 38 00:03:19,360 --> 00:03:22,685 It was enough to send her into an anaphylactic shock, 39 00:03:22,720 --> 00:03:26,640 the most severe response a person can have to an allergen. 40 00:03:26,675 --> 00:03:30,097 People always ask how we are, still, nearly five years on, 41 00:03:30,132 --> 00:03:33,485 people still ask how you are and it's still very upsetting. 42 00:03:33,520 --> 00:03:38,600 People think that on the outside, cos you're all right, that you are, but you're not. People say... 43 00:03:38,635 --> 00:03:42,200 Never will be, no parent would be. No. It's not just us, any parent. 44 00:03:42,235 --> 00:03:44,645 There's friends of hers now married, 45 00:03:44,680 --> 00:03:52,520 there's friends of hers have got children... That's what she should have done. 46 00:03:52,555 --> 00:03:56,917 She already knew what sort of wedding dress she wanted. 47 00:03:56,952 --> 00:04:01,280 She had her life planned out and it was torn away from her. 48 00:04:15,840 --> 00:04:20,725 For the Obatellis, the worry of peanut allergies did not end with Kate. 49 00:04:20,760 --> 00:04:26,200 Their two sons, Steven and Stuart, have a potentially fatal allergy to peanuts, too. 50 00:04:26,235 --> 00:04:34,285 That threat is... is... is hanging over their heads, 51 00:04:34,320 --> 00:04:38,000 and not only have they had to deal with Kate's, they've got that to deal with as well. 52 00:04:38,035 --> 00:04:43,765 It makes you neurotic, which the boys get cross at, because they 53 00:04:43,800 --> 00:04:48,960 think I'm fussing too much, but you don't want to lose another child. 54 00:04:51,240 --> 00:04:55,845 While fatalities following allergic reactions are rare, 55 00:04:55,880 --> 00:05:00,980 the number of children with peanut allergies has more than doubled in the past 15 years. 56 00:05:01,015 --> 00:05:06,080 Throughout the developed world, the number of recorded food allergy sufferers is rising, 57 00:05:06,115 --> 00:05:09,880 with admissions to hospitals for anaphylaxis going up by a staggering 700%. 58 00:05:14,240 --> 00:05:16,565 I am allergic to cats. 59 00:05:16,600 --> 00:05:18,920 I'm allergic to penicillin. Rice. 60 00:05:18,955 --> 00:05:20,617 Household dust. 61 00:05:20,652 --> 00:05:22,245 I have hayfever. 62 00:05:22,280 --> 00:05:26,920 The list of recorded allergies seems endless. I'm allergic to nuts. 63 00:05:26,955 --> 00:05:28,645 Chocolate. Engine oil. 64 00:05:28,680 --> 00:05:31,365 I'm allergic to... mostly everything. 65 00:05:31,400 --> 00:05:37,700 But how did allergies become such an important part of our everyday lives? 66 00:05:37,735 --> 00:05:44,000 Before the Second World War, allergies barely registered on the health agenda, 67 00:05:44,035 --> 00:05:48,960 but in the 1950s and 1960s more and more people started sneezing 68 00:05:48,995 --> 00:05:52,280 and wheezing and itching and scratching. 69 00:05:52,315 --> 00:05:54,445 Asthma and hayfever rates soared. 70 00:05:54,480 --> 00:05:57,365 But the allergy explosion didn't stop there. 71 00:05:57,400 --> 00:06:01,925 People began to develop new allergies, allergies to nuts, 72 00:06:01,960 --> 00:06:09,720 allergies to milk, allergies to washing powder, to fruits, to dust, to latex. The list goes on. 73 00:06:09,755 --> 00:06:14,760 This patient is allergic to cat fur, fungi and grass pollens. 74 00:06:17,680 --> 00:06:21,565 Whatever the trigger, allergic reactions all have one thing in common. 75 00:06:21,600 --> 00:06:28,640 They happen when our body's immune system overreacts to everyday substances. 76 00:06:28,675 --> 00:06:32,280 Why some people's bodies should react in this way 77 00:06:32,315 --> 00:06:34,045 and why allergies are increasing 78 00:06:34,080 --> 00:06:37,000 has intrigued scientists for decades. 79 00:06:41,360 --> 00:06:46,325 40 years ago, scientists thought they may have stumbled on the answer. 80 00:06:46,360 --> 00:06:52,280 It lay 1,500 miles off the coast of Africa on the most remote inhabited island on Earth. 81 00:07:02,800 --> 00:07:06,080 Isolated from the outside world for much of its history, 82 00:07:06,115 --> 00:07:09,325 it's still only reached by a seven-day boat journey. 83 00:07:09,360 --> 00:07:14,565 Tristan da Cunha has always been a place of great scientific interest. 84 00:07:14,600 --> 00:07:19,840 But there is far more than just its remoteness that makes it so fascinating. 85 00:07:24,960 --> 00:07:27,925 Five-year-old Randall has acute asthma. 86 00:07:27,960 --> 00:07:33,560 His symptoms are so severe that he suffers monthly attacks 87 00:07:33,595 --> 00:07:39,160 and is often forced to take medication every few hours. 88 00:07:39,195 --> 00:07:42,057 Some people may have asthma in certain ways, 89 00:07:42,092 --> 00:07:44,920 but the way that Randall has it is quite... 90 00:07:44,955 --> 00:07:48,325 it's like it's really serious. 91 00:07:48,360 --> 00:07:56,320 He's like a ticking time bomb, because it can just pop up any time, and then all of sudden... 92 00:07:56,355 --> 00:08:04,280 he may happen to take the wrong move or he caught the wrong thing, whatever, and it's there. 93 00:08:04,315 --> 00:08:08,805 But Randall is not the only asthmatic in the family. 94 00:08:08,840 --> 00:08:17,240 My son's got asthma, my elder sister has asthma, my dad has asthma. 95 00:08:19,040 --> 00:08:24,100 He's got a brother and two sisters that also has asthma. 96 00:08:24,135 --> 00:08:29,125 Also, my mum's dad is also... he's also asthmatic as well. 97 00:08:29,160 --> 00:08:37,400 In the late '60s, I had one of my cousins that died of asthma at the age of nine. 98 00:08:37,435 --> 00:08:40,605 Is it in every generation in your family? 99 00:08:40,640 --> 00:08:45,680 Yeah, like I said, from there up to my sister and to my dad, 100 00:08:45,715 --> 00:08:48,880 all falls back to... both sides. 101 00:08:51,320 --> 00:08:56,760 The Repetto family have suffered from asthma for over four generations, 102 00:08:56,795 --> 00:09:00,085 but on Tristan Da Cunha they are not alone. 103 00:09:00,120 --> 00:09:03,880 Asthma affects every single family on the island. 104 00:09:09,720 --> 00:09:15,525 Almost half of the 266 inhabitants suffer from asthma. 105 00:09:15,560 --> 00:09:21,680 It has the highest prevalence of the disease anywhere in the world. 106 00:09:23,520 --> 00:09:29,080 When it was first discovered, this mysterious phenomenon baffled scientists. 107 00:09:29,115 --> 00:09:31,565 Why would such a tiny isolated community 108 00:09:31,600 --> 00:09:35,720 have such a disproportionate number of people with asthma? 109 00:09:35,755 --> 00:09:39,805 Was it something peculiar about the people or the environment? 110 00:09:39,840 --> 00:09:45,160 It's a mystery to which Noe Zamel has dedicated his career to trying to solve. 111 00:09:45,195 --> 00:09:48,325 In the early 1960s, as a young graduate student, 112 00:09:48,360 --> 00:09:52,520 Zamel was involved in conducting a series of examinations on the islanders 113 00:09:52,555 --> 00:09:55,680 after they were forced to flee their homes 114 00:09:55,715 --> 00:09:58,125 following a volcanic eruption. 115 00:09:58,160 --> 00:10:03,200 There was rumours that... asthma was very prevalent in that community, 116 00:10:03,235 --> 00:10:05,925 but it was never tested objectively. 117 00:10:05,960 --> 00:10:10,600 So I got in touch with the Tristanians for the first time 118 00:10:10,635 --> 00:10:13,285 by performing pulmonary function tests, 119 00:10:13,320 --> 00:10:16,765 and I was amazed that virtually every second one that 120 00:10:16,800 --> 00:10:21,840 I tested had evidence of airways obstruction caused by asthma. 121 00:10:21,875 --> 00:10:25,165 Never having witnessed anything like it before, 122 00:10:25,200 --> 00:10:28,920 Zamel believed that if he could uncover the cause of asthma 123 00:10:28,955 --> 00:10:32,640 on Tristan da Cunha, it could lead to a better understanding 124 00:10:32,675 --> 00:10:34,880 of the disease throughout the world. 125 00:10:36,720 --> 00:10:41,880 Zamel never forgot what he'd observed, but it would be another 30 years before 126 00:10:41,915 --> 00:10:45,680 he got the opportunity to visit the island for himself 127 00:10:45,715 --> 00:10:48,725 and carry out his own comprehensive study. 128 00:10:48,760 --> 00:10:54,805 The excitement was contagious to everyone, the preparation. 129 00:10:54,840 --> 00:10:59,840 There was not a single person that didn't hear about this remote place 130 00:10:59,875 --> 00:11:04,400 with this crazy doctor about to do his crazy study, 131 00:11:04,435 --> 00:11:09,325 and from laughing it became serious 132 00:11:09,360 --> 00:11:13,120 and we did come and got the permission, and we did the study. 133 00:11:16,960 --> 00:11:22,680 In the course of two visits to the island, Zamel has run detailed tests on virtually every islander. 134 00:11:24,520 --> 00:11:27,965 He has also traced the family lineage 135 00:11:28,000 --> 00:11:32,520 of every surname on the island, all seven of them. 136 00:11:34,280 --> 00:11:36,845 In this graveyard there's only seven family names. 137 00:11:36,880 --> 00:11:42,240 In fact there is only seven names in the entire island, like Hagan... 138 00:11:42,275 --> 00:11:47,685 Swain, Lavarello... 139 00:11:47,720 --> 00:11:52,040 Over here Green, over here Rogers, 140 00:11:52,075 --> 00:11:55,640 Glass, Glass... 141 00:11:56,800 --> 00:12:00,605 Over there... Repetto, Repetto. 142 00:12:00,640 --> 00:12:05,600 Everybody in the island is a cousin of each other several times over, 143 00:12:05,635 --> 00:12:08,085 some of them about 50 times over, 144 00:12:08,120 --> 00:12:12,460 and it has been like this for many generations, 145 00:12:12,495 --> 00:12:16,107 actually from the beginning of the first settlers. 146 00:12:16,142 --> 00:12:19,611 For a long time, scientists have been preoccupied 147 00:12:19,646 --> 00:12:23,045 with external irritants for diseases like asthma, 148 00:12:23,080 --> 00:12:26,640 but Zamel was convinced that in a community with such a prevalence of 149 00:12:26,675 --> 00:12:31,525 one disease and remarkable degree of inter-marriage 150 00:12:31,560 --> 00:12:36,480 that at least part of the answer had to lie in the genes. 151 00:12:36,515 --> 00:12:41,285 In an attempt to uncover the source of the disease, 152 00:12:41,320 --> 00:12:47,680 Zamel traced the lineage of every islander back as far as the very first settlers. 153 00:12:47,715 --> 00:12:51,717 In 1816, Tristan da Cunha was occupied by a garrison 154 00:12:51,752 --> 00:12:55,720 of British soldiers stationed to guard Napoleon, 155 00:12:55,755 --> 00:12:58,717 imprisoned on neighbouring St Helena. 156 00:12:58,752 --> 00:13:01,680 In the years following his death in 1827, 157 00:13:01,715 --> 00:13:03,965 five men settled on the island. 158 00:13:04,000 --> 00:13:10,160 As bachelors they sent for five women from St Helena to become their wives. 159 00:13:10,195 --> 00:13:13,400 Even though at the time asthma was an extremely rare condition, 160 00:13:13,435 --> 00:13:17,040 bizarrely, three of the five women had the disease. 161 00:13:20,080 --> 00:13:26,040 70 years later, the next people to arrive were two shipwrecked Italian sailors. 162 00:13:26,075 --> 00:13:30,325 Against all odds, both also suffered from asthma. 163 00:13:30,360 --> 00:13:37,520 Three of the matriarchs that came to the island from St Helena in 1827 164 00:13:37,555 --> 00:13:41,685 had asthma and brought a gene of asthma to the island. 165 00:13:41,720 --> 00:13:47,140 Two men brought the gene of asthma to Tristan da Cunha from Italy, 166 00:13:47,175 --> 00:13:52,560 two sailors that were shipwrecked in Tristan da Cunha in 1892, 167 00:13:52,595 --> 00:13:56,165 Gaetano Lavarello and Andrea Repetto. 168 00:13:56,200 --> 00:14:01,925 In fact, Andrea Repetto died at age 44 of severe asthma. 169 00:14:01,960 --> 00:14:06,760 Two chance events in the island's early history played a key role 170 00:14:06,795 --> 00:14:10,617 in spreading asthma to all subsequent generations. 171 00:14:10,652 --> 00:14:14,846 So no wonder that the original settlers that found 172 00:14:14,881 --> 00:14:19,320 all those seven families, more than 50% had asthma, 173 00:14:19,355 --> 00:14:23,257 no wonder that the descendants presently have about 174 00:14:23,292 --> 00:14:27,160 50% of asthma transmitted from the original settlers. 175 00:14:28,320 --> 00:14:32,840 While this tiny community has suffered the consequence of their unique history, 176 00:14:32,875 --> 00:14:38,080 their rare genetic homogeneity provided Zamel with a unique opportunity 177 00:14:38,115 --> 00:14:41,165 to unlock the secrets of the Tristanians' genes. 178 00:14:41,200 --> 00:14:45,680 Here there was a place to find a gene, was right here. 179 00:14:45,715 --> 00:14:51,280 This was the highest prevalence of asthma 180 00:14:51,315 --> 00:14:55,685 in the most homogenous gene pool. 181 00:14:55,720 --> 00:14:59,845 If we couldn't find the gene of asthma here, 182 00:14:59,880 --> 00:15:03,445 most likely we aren't going to find it anywhere else. 183 00:15:03,480 --> 00:15:09,380 After several years spent analysing the DNA of the asthmatic and non-asthmatic islanders, 184 00:15:09,415 --> 00:15:15,280 Zamel has eventually been able to identify a series of significant genetic differences. 185 00:15:15,315 --> 00:15:20,285 We found that the asthmatics had a difference in several regions 186 00:15:20,320 --> 00:15:26,240 of the chromosomes and one of them, the linkage in terms of significance was the highest 187 00:15:26,275 --> 00:15:32,320 and that was in the chromosome eleven in the short arm, a division called P-13. 188 00:15:32,355 --> 00:15:37,477 By comparing his findings with other asthmatic populations, 189 00:15:37,512 --> 00:15:42,600 the team has isolated one particular gene known as ESE-3. 190 00:15:44,560 --> 00:15:46,965 Let's see how you do. 191 00:15:47,000 --> 00:15:52,640 ESE-3 regulates a series of genes responsible for the deposition of collagen in the airways. 192 00:15:52,675 --> 00:15:57,000 If the gene is faulty, collagen is overproduced, constricting 193 00:15:57,035 --> 00:15:59,840 the airways and making breathing more difficult. 194 00:15:59,875 --> 00:16:01,240 And again? 195 00:16:06,040 --> 00:16:10,325 40 years after his first encounter with the Tristanians, 196 00:16:10,360 --> 00:16:16,160 Zamel had finally identified the very first genes involved in allergic asthma. 197 00:16:16,195 --> 00:16:21,317 We have this sense that by doing this study we are doing history. 198 00:16:21,352 --> 00:16:26,556 Scientists are supposed to be cool, detached, objective, but coming 199 00:16:26,591 --> 00:16:31,760 this place to obtain the data, it's one emotion after the other. 200 00:16:31,795 --> 00:16:35,125 It's absolutely exhilarating. 201 00:16:35,160 --> 00:16:39,960 Each and every one of us inherit a unique allergic imprint from our parents. 202 00:16:39,995 --> 00:16:44,760 This determines how susceptible we are to developing an allergic disease. 203 00:16:44,795 --> 00:16:48,765 But our genes do not tell the whole story. 204 00:16:48,800 --> 00:16:54,040 The genes play just a partial role in allergen and asthma. 205 00:16:54,075 --> 00:16:57,005 In asthma probably between 30 to 40%, 206 00:16:57,040 --> 00:17:03,405 so more than 50% of the causes of asthma are not genetic. 207 00:17:03,440 --> 00:17:08,520 The Tristan da Cunha findings does not explain the whole problem 208 00:17:08,555 --> 00:17:11,165 of allergy in asthma, surely not. 209 00:17:11,200 --> 00:17:14,080 It's just a small piece in the jigsaw. 210 00:17:17,760 --> 00:17:23,400 Over 8,000 miles away on the other side of the world, there is a different suspect entirely. 211 00:17:36,280 --> 00:17:41,640 Our genes take thousands of years to change and evolve, 212 00:17:41,675 --> 00:17:44,365 yet in certain parts of the world, 213 00:17:44,400 --> 00:17:47,760 allergy rates have more than trebled in the past few decades. 214 00:17:54,880 --> 00:18:00,040 Something else about the way in which we live has to be responsible. 215 00:18:12,440 --> 00:18:15,400 When she starts coughing she says, 216 00:18:15,435 --> 00:18:17,725 "Mummy, my throat hurts a lot. " 217 00:18:17,760 --> 00:18:22,520 When we go to sleep, she usually coughs all night non-stop. 218 00:18:22,555 --> 00:18:25,925 She feels suffocated. 219 00:18:25,960 --> 00:18:32,960 Erica Olvera lives with her two children in Los Angeles. 220 00:18:32,995 --> 00:18:39,925 Her daughter Natalie has severe asthma, a condition that 221 00:18:39,960 --> 00:18:43,520 only developed after the family moved from Mexico to California. 222 00:18:45,160 --> 00:18:51,680 Erica is convinced that her daughter's illness is directly related to where they live. 223 00:18:51,715 --> 00:18:57,520 Around all the schools near here there is a refinery on one side. 224 00:18:57,555 --> 00:19:00,765 On the other side there is a freeway. 225 00:19:00,800 --> 00:19:06,600 They are surrounded by contamination everywhere. 226 00:19:14,480 --> 00:19:17,800 Professor Frank Gilliland has been studying the effects of pollution 227 00:19:17,835 --> 00:19:19,245 on families like the Olveras. 228 00:19:19,280 --> 00:19:23,840 What he's discovered has revolutionised our understanding of 229 00:19:23,875 --> 00:19:29,457 the link between the environment and allergies such as asthma. 230 00:19:29,492 --> 00:19:35,040 We know that traffic is a major issue across the developed world. 231 00:19:35,075 --> 00:19:38,597 In every city there's huge amounts of traffic. 232 00:19:38,632 --> 00:19:41,616 It's worrying because the effects are real, 233 00:19:41,651 --> 00:19:44,445 they're large and the levels of exposure 234 00:19:44,480 --> 00:19:47,240 especially to traffic, are increasing. 235 00:19:50,440 --> 00:19:55,220 Gilliland fears that until now the most dangerous effects of pollution 236 00:19:55,255 --> 00:19:59,965 may have been ignored because they are invisible to the human eye. 237 00:20:00,000 --> 00:20:06,280 The air we breathe is an aerosol which means it has particles in it as well as gases. 238 00:20:06,315 --> 00:20:10,237 These particles can be breathed in and they're small enough that 239 00:20:10,272 --> 00:20:14,160 they go into the deepest part of the lungs and are deposited, 240 00:20:14,195 --> 00:20:16,405 and they're coated with a bunch of metals 241 00:20:16,440 --> 00:20:23,640 and other toxic chemicals that can then reside in the lung and produce adverse effects. 242 00:20:25,480 --> 00:20:29,440 In order to directly assess the impact of this 243 00:20:29,475 --> 00:20:31,245 particulate air pollution, 244 00:20:31,280 --> 00:20:34,885 Gilliland and his team conducted a series of clinical trials. 245 00:20:34,920 --> 00:20:39,760 A number of subjects were given a nose spray containing diesel particles 246 00:20:39,795 --> 00:20:44,600 equivalent to the levels experienced during 40 hours in southern California. 247 00:20:44,635 --> 00:20:47,840 Others were given a dose of a common ragweed allergen 248 00:20:47,875 --> 00:20:50,877 or of diesel particles and allergen combined. 249 00:20:50,912 --> 00:20:53,880 Their allergic responses were then measured. 250 00:20:59,360 --> 00:21:05,080 The most dramatic finding was that allergen alone would have, say, a response 251 00:21:05,115 --> 00:21:06,805 of one unit on one of our measures 252 00:21:06,840 --> 00:21:10,765 and if you combine diesel exhaust and allergen that would be 20-fold. 253 00:21:10,800 --> 00:21:15,620 Gilliland had shown that for some people, simply living near a major road 254 00:21:15,655 --> 00:21:20,405 could dramatically increase the risk of developing an allergic disease. 255 00:21:20,440 --> 00:21:27,325 In the past, it's generally believed that air pollution causes respiratory symptoms 256 00:21:27,360 --> 00:21:34,160 and asthma and allergies to get worse, however that air pollution didn't cause asthma or allergies. 257 00:21:34,195 --> 00:21:38,977 The emerging data is that air pollution does indeed 258 00:21:39,012 --> 00:21:43,760 cause asthma, cause allergy, as well as exacerbating it 259 00:21:43,795 --> 00:21:46,645 once you already have those conditions. 260 00:21:46,680 --> 00:21:51,760 Within the 150 or 300 metres of major roadways or freeways 261 00:21:51,795 --> 00:21:55,645 are those who are at risk from this exposure, 262 00:21:55,680 --> 00:22:03,160 so it's really in this hot zone around busy freeways that seem to have the potential to induce asthma. 263 00:22:03,195 --> 00:22:08,480 TRANSLATION: We would like to go somewhere else but we can't. 264 00:22:08,515 --> 00:22:10,365 Where do we go to? 265 00:22:10,400 --> 00:22:17,040 We haven't got any money, we have nowhere to go. 266 00:22:19,440 --> 00:22:21,485 Living in a polluted environment 267 00:22:21,520 --> 00:22:25,960 can make the difference between developing an allergic disease or not. 268 00:22:25,995 --> 00:22:30,045 But the risk from the air we breathe may be just one of the ways 269 00:22:30,080 --> 00:22:35,560 ways our changing lifestyle is making us increasingly vulnerable to allergies. 270 00:22:53,360 --> 00:22:57,080 Sometimes I can stay in the bath up to two hours just to get 271 00:22:57,115 --> 00:23:00,440 the skin proper soft, and my legs are terrible. 272 00:23:00,475 --> 00:23:02,165 They've been so bad lately. 273 00:23:02,200 --> 00:23:06,040 It's just sometimes I can't walk with them and it really hurts. 274 00:23:06,075 --> 00:23:08,285 And that's just why, really. 275 00:23:08,320 --> 00:23:16,680 14-year-old Billy Perkins has a rare genetic skin disorder knows as Netherton Syndrome. 276 00:23:16,715 --> 00:23:22,725 His skin sheds on a permanent basis and he's sort of very red in appearance 277 00:23:22,760 --> 00:23:28,000 so he has to take several baths a day and apply creams from head to toe constantly, 278 00:23:28,035 --> 00:23:30,880 otherwise he dries out and goes quite tight. 279 00:23:30,915 --> 00:23:33,165 It also affects his hair. 280 00:23:33,200 --> 00:23:37,600 It's called bamboo hair, because it looks like a strand of bamboo under a microscope. 281 00:23:37,635 --> 00:23:41,800 It grows but it breaks off very, very easy so his hair is quite sparse. 282 00:23:44,640 --> 00:23:50,960 Nethertons patients all have very similar symptoms - thin, red scaly skin and brittle hair. 283 00:23:50,995 --> 00:23:55,720 But they also have something else in common. 284 00:23:55,755 --> 00:23:58,760 They all suffer from allergies. 285 00:24:02,880 --> 00:24:06,645 No, don't cos I'm not sure if I'm allergic to that. 286 00:24:06,680 --> 00:24:11,085 Netherton Syndrome also means that Billy suffers from multiple allergies. 287 00:24:11,120 --> 00:24:18,960 Billy is allergic to nuts, shellfish, kiwi fruit, latex gloves, bee stings and wasp stings. 288 00:24:18,995 --> 00:24:21,920 It's just something that you learn to live with. 289 00:24:21,955 --> 00:24:24,600 "Ingredients cannot guarantee nut free. " 290 00:24:24,635 --> 00:24:26,405 Why does it say no nuts then? 291 00:24:26,440 --> 00:24:30,880 My lips swell and my eyes puff up and then sometimes I might pass out. 292 00:24:30,915 --> 00:24:33,845 And it stops my breathing as well. 293 00:24:33,880 --> 00:24:38,280 I get really scared, cos you don't know what is going to happen next. 294 00:24:38,315 --> 00:24:41,085 Do you wish that you didn't have the allergy? 295 00:24:41,120 --> 00:24:45,680 Oh, yeah, a lot. I'd rather them go than anything else. 296 00:24:45,715 --> 00:24:47,760 Cos they're the biggest problem. 297 00:24:49,920 --> 00:24:52,045 Hello. How are you? OK. 298 00:24:52,080 --> 00:24:56,040 Billy's doctor, Professor John Harper, has been treating 299 00:24:56,075 --> 00:24:59,160 children with Netherton Syndrome for over 20 years. 300 00:24:59,195 --> 00:25:01,765 The skin seems to be doing reasonably well. 301 00:25:01,800 --> 00:25:04,080 Do you think we could have a little look at you? 302 00:25:04,115 --> 00:25:06,577 He's long been convinced that the link between 303 00:25:06,612 --> 00:25:09,040 Netherton syndrome and allergies was significant. 304 00:25:09,075 --> 00:25:10,685 Can I look at your head? 305 00:25:10,720 --> 00:25:15,260 Having seen more and more children with Netherton syndrome, 306 00:25:15,295 --> 00:25:19,800 I realise they are all at risk of a wide range of allergies, 307 00:25:19,835 --> 00:25:21,685 so that's what makes Nethertons 308 00:25:21,720 --> 00:25:24,160 although it's a very rare disease, very special. 309 00:25:27,240 --> 00:25:32,160 Together with a team of experts, Harper and immunologist Robin Callard, 310 00:25:32,195 --> 00:25:36,600 work to isolate and analyse the genes involved in the condition. 311 00:25:36,635 --> 00:25:39,685 But that's consistent with the... 312 00:25:39,720 --> 00:25:42,765 What they discovered was that in Nethertons patients, 313 00:25:42,800 --> 00:25:47,400 an important gene responsible for making a key protein known as Lekti is defective. 314 00:25:49,760 --> 00:25:55,640 In Netherton syndrome you do not have the production of Lekti. It's absent. 315 00:25:55,675 --> 00:26:00,565 If it's absent then it disturbs 316 00:26:00,600 --> 00:26:06,285 the whole protein biology required to form a normal skin barrier. 317 00:26:06,320 --> 00:26:12,920 This was the first insight that we had that the skin barrier might be linked to allergy in some way. 318 00:26:12,955 --> 00:26:16,485 OK. 319 00:26:16,520 --> 00:26:20,900 Lekti is a protein which makes and maintains the surface layer of the skin. 320 00:26:20,935 --> 00:26:25,280 When it is missing the skin barrier is deficient, like a dam with holes in it. 321 00:26:30,920 --> 00:26:35,565 It was an important clue as to why Netherton patients were so allergic. 322 00:26:35,600 --> 00:26:40,720 They were somehow becoming sensitised to allergens through their damaged skin. 323 00:26:40,755 --> 00:26:45,400 It's a discovery that doesn't only apply to Nethertons patients. 324 00:26:46,440 --> 00:26:50,160 Harper and Callard have linked similar genetic differences 325 00:26:50,195 --> 00:26:52,640 to other skin conditions such as eczema. 326 00:26:54,800 --> 00:26:58,405 But it may also apply to us all. 327 00:26:58,440 --> 00:27:05,280 We decided to just remove the skin barrier which is done very simply just with Sellotape, 328 00:27:05,315 --> 00:27:08,645 but once that's removed without actually damaging the skin, 329 00:27:08,680 --> 00:27:12,885 without actually going into the inner layers, without causing any bleeding, 330 00:27:12,920 --> 00:27:16,840 when you put the antigen on the skin then it elicits this very powerful response. 331 00:27:18,560 --> 00:27:22,565 By simply removing a layer of skin, 332 00:27:22,600 --> 00:27:28,005 Callard had shown it was possible to provoke a strong allergic reaction. 333 00:27:28,040 --> 00:27:33,560 This revolutionary new idea may shed light on why allergies are on the rise in the developed world. 334 00:27:33,595 --> 00:27:38,240 We have gone in Britain alone from a time when perhaps 50 or 60 years ago 335 00:27:38,275 --> 00:27:41,160 we had a bath in a tin bath in the kitchen once a week 336 00:27:41,195 --> 00:27:44,005 to all sorts of products that we use on our skin. 337 00:27:44,040 --> 00:27:50,000 These very strong detergents, rough exfoliating agents, the loofahs and so on. 338 00:27:50,035 --> 00:27:55,680 So I think our hygiene habits can result in damage to the skin barrier. 339 00:27:58,640 --> 00:28:03,325 If we are self-inflicting injury on our skin barrier, 340 00:28:03,360 --> 00:28:07,180 even if it's in a very mild way but on a regular daily basis, 341 00:28:07,215 --> 00:28:11,000 perhaps we are uncovering a vulnerability to allergy that 342 00:28:11,035 --> 00:28:13,480 wouldn't otherwise have been apparent. 343 00:28:19,640 --> 00:28:24,040 The discovery that we are becoming increasingly exposed to allergens 344 00:28:24,075 --> 00:28:26,645 through damaged skin and polluted air 345 00:28:26,680 --> 00:28:33,480 has significantly contributed to science's understanding of the global allergy epidemic. 346 00:28:35,880 --> 00:28:38,820 But in order to really understand why allergies 347 00:28:38,855 --> 00:28:41,760 have risen so dramatically in recent years, 348 00:28:41,795 --> 00:28:44,005 scientists are turning their attention 349 00:28:44,040 --> 00:28:47,760 to the parts of the world where the rate of increase is most extreme. 350 00:29:00,240 --> 00:29:03,920 Barbados may be the archetypal tropical island paradise, 351 00:29:03,955 --> 00:29:06,400 but it too is being plagued by allergies. 352 00:29:15,160 --> 00:29:18,560 Asthma now affects over 20% of the population. 353 00:29:23,320 --> 00:29:26,525 Having asthma is frightening. 354 00:29:26,560 --> 00:29:29,325 You want to breathe but you can't. 355 00:29:29,360 --> 00:29:33,840 That is... it can't be put into words, it just cannot be. 356 00:29:33,875 --> 00:29:36,297 It is really scary. 357 00:29:36,332 --> 00:29:38,685 Deep breath in. Out. 358 00:29:38,720 --> 00:29:43,525 Dr Harold Watson has been an A&E physician for 20 years. 359 00:29:43,560 --> 00:29:49,000 An asthmatic himself, he runs the A&E's dedicated asthma bay. 360 00:29:51,960 --> 00:29:57,245 In the 1990s we started with a thousand visits of asthma, 361 00:29:57,280 --> 00:30:03,480 now we are seeing 11,000 people out of 45,000 visits in our department. 362 00:30:04,960 --> 00:30:08,765 Not only have doctors here experienced a tenfold increase 363 00:30:08,800 --> 00:30:13,040 in the last 20 years, the cases they are treating are also getting 364 00:30:13,075 --> 00:30:14,805 more and more severe. 365 00:30:14,840 --> 00:30:19,420 Asthma frightens people because I've seen people who have gone 366 00:30:19,455 --> 00:30:24,027 from talking to me to collapse within a matter of minutes. 367 00:30:24,062 --> 00:30:28,600 I've had to deal with asthmatics who have died in front of me. 368 00:30:32,880 --> 00:30:36,340 Just why Barbados should be so severely affected 369 00:30:36,375 --> 00:30:40,787 has mystified scientists from around the world. 370 00:30:40,822 --> 00:30:44,691 We think of asthma these days as an epidemic 371 00:30:44,726 --> 00:30:48,525 because it's increasing at such a rapid rate, 372 00:30:48,560 --> 00:30:51,925 and a rate by which it's very difficult for scientists 373 00:30:51,960 --> 00:30:56,360 and physicians to get a handle on what's causing that increase. 374 00:30:57,920 --> 00:31:02,060 But Kathleen Barnes believes that Barbados might offer us our best 375 00:31:02,095 --> 00:31:06,200 hope of understanding just what lies behind the global allergy crisis. 376 00:31:08,160 --> 00:31:12,160 One of the reasons that we're so excited about conducting a study 377 00:31:12,195 --> 00:31:14,205 on asthma here in Barbados is that 378 00:31:14,240 --> 00:31:17,640 it really is a microcosm of what's happening globally. 379 00:31:17,675 --> 00:31:21,005 It's gone through this very rapid period of change 380 00:31:21,040 --> 00:31:25,800 over a very short period of time which has been beneficial for us 381 00:31:25,835 --> 00:31:28,960 in trying to understand some of the environmental factors 382 00:31:28,995 --> 00:31:32,205 involved in asthma that we can't capture 383 00:31:32,240 --> 00:31:36,400 in the more developed societies such as the United States or the UK. 384 00:31:43,480 --> 00:31:47,405 In the last two decades Barbados has been radically transformed. 385 00:31:47,440 --> 00:31:52,240 Its people have been rapidly swapping their traditional rural environment 386 00:31:52,275 --> 00:31:55,840 for the modern westernised one of the island's towns and cities. 387 00:32:04,200 --> 00:32:08,600 This dramatic transformation has offered Barnes a rare opportunity 388 00:32:08,635 --> 00:32:12,360 to witness the effects of these changes as they take place. 389 00:32:15,440 --> 00:32:19,800 The explanation for the increase in asthma here could have something 390 00:32:19,835 --> 00:32:23,737 to do with this transition from the traditional chattel homes 391 00:32:23,772 --> 00:32:27,786 to the more modern structures because, in fact, that timeframe 392 00:32:27,821 --> 00:32:31,800 sort of converged with when they began seeing more asthma, 393 00:32:31,835 --> 00:32:33,800 more severe asthma on the island. 394 00:32:36,560 --> 00:32:41,120 Over the past 20 years, Barnes and her team have analysed 395 00:32:41,155 --> 00:32:43,285 the homes on the island in minute detail, 396 00:32:43,320 --> 00:32:46,760 collecting dust samples and monitoring allergen levels. 397 00:32:46,795 --> 00:32:49,885 What they discovered surprised them. 398 00:32:49,920 --> 00:32:54,000 We expected to see many many house dust mites in these chattel houses 399 00:32:54,035 --> 00:32:57,085 and in fact we did, but what was interesting 400 00:32:57,120 --> 00:33:01,400 is that we found higher levels in the better-built concrete structures. 401 00:33:01,435 --> 00:33:05,365 So what we believe is that in the modern home, 402 00:33:05,400 --> 00:33:09,120 there are a variety of factors that contribute to this exposure. 403 00:33:09,155 --> 00:33:14,520 Indoor carpeting, better upholstered furniture and so on. 404 00:33:14,555 --> 00:33:16,045 All of these things combined 405 00:33:16,080 --> 00:33:18,680 contributed to these higher levels of allergen. 406 00:33:22,400 --> 00:33:25,720 The discovery that the modern home greatly increases exposure 407 00:33:25,755 --> 00:33:28,640 to dust mite allergen was significant. 408 00:33:30,120 --> 00:33:33,800 But Barnes believes it is just one of many lifestyle changes 409 00:33:33,835 --> 00:33:36,120 that lie behind the allergy crisis here. 410 00:33:38,640 --> 00:33:40,645 It's not the only answer 411 00:33:40,680 --> 00:33:43,045 because during this very short period of time 412 00:33:43,080 --> 00:33:47,000 there have been a number of other changes that we know to be important 413 00:33:47,035 --> 00:33:50,920 including changes in diet, the way people eat, their physical activity, 414 00:33:50,955 --> 00:33:54,320 and probably most importantly the number of cars on the island. 415 00:33:54,355 --> 00:33:58,297 So I suppose the irony here is that we're all striving 416 00:33:58,332 --> 00:34:02,205 for living in the most modern fashion as possible. 417 00:34:02,240 --> 00:34:06,320 It is the ultimate dream for everyone and with that no doubt 418 00:34:06,355 --> 00:34:10,400 comes certain advantages over a more traditional way of living. 419 00:34:10,435 --> 00:34:13,437 That said, the irony is that, in fact, 420 00:34:13,472 --> 00:34:16,405 it's contributing to a microenvironment 421 00:34:16,440 --> 00:34:19,240 that might actually not be so good for our health. 422 00:34:22,360 --> 00:34:26,240 But why should modern life have such a dramatic impact on our health? 423 00:34:29,240 --> 00:34:32,440 Part of the answer came when scientists began to question 424 00:34:32,475 --> 00:34:35,600 what possible purpose allergies might serve. 425 00:34:37,800 --> 00:34:42,840 If we look back into our ancient past, perhaps that holds the answer. 426 00:34:44,360 --> 00:34:49,120 In certain parts of rural Africa there was no asthma allergic disease at all 427 00:34:49,155 --> 00:34:54,017 and when those same people modernised or moved out of rural Africa into 428 00:34:54,052 --> 00:34:58,880 the urban setting, suddenly there was more asthma and allergic disease. 429 00:35:01,000 --> 00:35:03,520 As they began to dig a little deeper, 430 00:35:03,555 --> 00:35:06,040 scientists made an important observation. 431 00:35:08,720 --> 00:35:11,925 The antibody known as IGE, which the body uses to fight 432 00:35:11,960 --> 00:35:17,920 allergic diseases, also serves another very different purpose. 433 00:35:19,000 --> 00:35:22,405 IGE is that antibody in our immune system 434 00:35:22,440 --> 00:35:27,680 that's specifically involved in allergic disease and asthma. 435 00:35:27,715 --> 00:35:31,365 But IGE didn't evolve because of asthma and allergies. 436 00:35:31,400 --> 00:35:34,880 It turns out that it actually evolved as a protective mechanism 437 00:35:34,915 --> 00:35:37,925 against the worm, the kinds of parasites 438 00:35:37,960 --> 00:35:42,080 that caused diseases like ascaris, schistosomiasis and so on. 439 00:35:42,115 --> 00:35:46,200 So in rural Africa, which was endemic for these parasites, 440 00:35:46,235 --> 00:35:49,760 these people produced really high levels of IGE. 441 00:35:49,795 --> 00:35:52,445 If you remove them from that situation, 442 00:35:52,480 --> 00:35:56,840 they still are genetically predisposed to produce lots of IGE, 443 00:35:56,875 --> 00:35:59,765 but the IGE has nothing to bind to any more. 444 00:35:59,800 --> 00:36:03,805 There's no more worm. And so oddly enough it binds to these very 445 00:36:03,840 --> 00:36:08,760 innocuous proteins such as house dust mite allergens, cockroach and so on. 446 00:36:08,795 --> 00:36:13,157 The same immune mechanism the body uses to fight parasites 447 00:36:13,192 --> 00:36:17,136 is also the one it employs to fight harmless allergens. 448 00:36:17,171 --> 00:36:21,080 What evolved to protect us in one type of environment 449 00:36:21,115 --> 00:36:23,525 has now become a liability. 450 00:36:23,560 --> 00:36:27,800 So one way we could think of this, and it's potentially controversial, 451 00:36:27,835 --> 00:36:33,037 is that we're somewhat out of synch with what we originally evolved for. 452 00:36:33,072 --> 00:36:37,656 So in other words, this protective mechanism called IGE that suited us 453 00:36:37,691 --> 00:36:42,240 very well in an environment where we were exposed to lots of parasites, 454 00:36:42,275 --> 00:36:45,217 taken from that environment in what is in essence 455 00:36:45,252 --> 00:36:48,160 a very short period of time in our human history, 456 00:36:48,195 --> 00:36:50,877 it no longer serves its original purpose 457 00:36:50,912 --> 00:36:53,560 and in fact has gone awry, if you will. 458 00:36:56,960 --> 00:36:58,605 From the air we breathe 459 00:36:58,640 --> 00:37:02,005 to the way we wash and the homes in which we live, 460 00:37:02,040 --> 00:37:06,960 our biology appears to be increasingly out of step with the world we are creating. 461 00:37:06,995 --> 00:37:09,805 But how far will this go? 462 00:37:09,840 --> 00:37:13,285 Could we eventually become allergic to everything? 463 00:37:13,320 --> 00:37:17,320 There are already some people who believe themselves to be allergic 464 00:37:17,355 --> 00:37:19,240 to modern life itself. 465 00:37:20,800 --> 00:37:22,660 My name is Steven. 466 00:37:22,695 --> 00:37:24,485 I had a law practice. 467 00:37:24,520 --> 00:37:29,960 Every time I went into the office I would just be really sick. 468 00:37:29,995 --> 00:37:31,605 I didn't know what it was... 469 00:37:31,640 --> 00:37:33,965 I was 33. I was working as a fire fighter. 470 00:37:34,000 --> 00:37:38,960 The heat from the fire on the side of the building was vaporising all 471 00:37:38,995 --> 00:37:42,880 the chemicals, all the plastics, the carpet, rooms were being... 472 00:37:42,915 --> 00:37:45,085 I kept having these migraine headaches, 473 00:37:45,120 --> 00:37:49,880 migraine headaches which were so intense that they'd last for 24 hours 474 00:37:49,915 --> 00:37:55,520 with vomiting and diarrhoea and when they started to go away, 475 00:37:55,555 --> 00:37:58,565 I would have suicidal thoughts. 476 00:37:58,600 --> 00:38:04,280 The people in this self-help group all suffer from a highly contentious 477 00:38:04,315 --> 00:38:08,920 condition known as Multiple Chemical Sensitivity, or MCS. 478 00:38:08,955 --> 00:38:11,485 They believe they are highly allergic 479 00:38:11,520 --> 00:38:15,085 to virtually every modern chemical in the environment. 480 00:38:15,120 --> 00:38:20,020 I counted it up and I had a list of about 40 symptoms and I kept 481 00:38:20,055 --> 00:38:24,920 going into different doctors, you know, crying, "What is going on?" 482 00:38:24,955 --> 00:38:27,085 And I remember one allergy doctor... 483 00:38:27,120 --> 00:38:30,500 Many of those here feel that they are so sensitive that they fear 484 00:38:30,535 --> 00:38:33,880 the slightest contact with us could provoke painful symptoms. 485 00:38:35,560 --> 00:38:39,380 As a result they have requested we only film from a distance 486 00:38:39,415 --> 00:38:43,200 and cover our equipment in tin foil to prevent contamination. 487 00:38:43,235 --> 00:38:46,517 I started to have to go on emergency oxygen 488 00:38:46,552 --> 00:38:49,765 cos I stopped breathing and I had to... 489 00:38:49,800 --> 00:38:53,680 Nancy Van Afflen has one of the most severe cases of MCS. 490 00:38:55,440 --> 00:38:58,765 Unable to cope with the modern environment, she has been forced 491 00:38:58,800 --> 00:39:02,920 to sell her home and seek refuge in the remote Texas town of Wimberley. 492 00:39:10,520 --> 00:39:12,725 What are the gloves for? 493 00:39:12,760 --> 00:39:17,720 I'm allergic to vinyl and the polyester. 494 00:39:20,560 --> 00:39:22,720 Why do you have the oxygen in the car? 495 00:39:24,040 --> 00:39:26,485 So that I won't get sick. 496 00:39:26,520 --> 00:39:30,965 All you're doing is building up... um... 497 00:39:31,000 --> 00:39:34,125 toxins in the air all around you, clouds of them. 498 00:39:34,160 --> 00:39:37,000 Even if you can see them that's all you're breathing in. 499 00:39:37,035 --> 00:39:39,165 You can't stop it from coming in. 500 00:39:39,200 --> 00:39:42,480 You can protect yourself from a little bit of it, but that's why 501 00:39:42,515 --> 00:39:45,760 I use this machine back here with the charcoal filter in it. 502 00:39:45,795 --> 00:39:48,897 I turn that thing on, start cleaning my air, 503 00:39:48,932 --> 00:39:52,000 put my oxygen on and give myself a break. 504 00:39:53,400 --> 00:39:56,520 And it's relaxing. It actually makes you more alert. 505 00:39:56,555 --> 00:39:57,960 You're a better driver. 506 00:40:01,440 --> 00:40:05,540 Convinced that everything around her is a potential danger, 507 00:40:05,575 --> 00:40:09,640 Nancy has spent the past year rebuilding her home in an attempt 508 00:40:09,675 --> 00:40:12,517 to protect herself from the thousands of chemicals 509 00:40:12,552 --> 00:40:15,360 most of us come into contact with on a daily basis. 510 00:40:16,920 --> 00:40:19,965 You get anxiety attacks, you swell up, 511 00:40:20,000 --> 00:40:23,000 your face starts swelling, your eyes swell, 512 00:40:23,035 --> 00:40:25,965 you get sick, your pain levels go very high 513 00:40:26,000 --> 00:40:29,920 and you've got to be able to get away into some kind of place to run 514 00:40:29,955 --> 00:40:33,680 that's safe to get better or you're in serious trouble. 515 00:40:33,715 --> 00:40:36,000 It's just downhill all the way. 516 00:40:37,120 --> 00:40:39,525 Till you pass out and you don't live any more 517 00:40:39,560 --> 00:40:42,720 cos you get too many things happening and you die. 518 00:40:42,755 --> 00:40:45,085 This is a five inch HEPA down here 519 00:40:45,120 --> 00:40:49,620 which is a filter which will take out whatever's in the air. 520 00:40:49,655 --> 00:40:53,827 This is new plywood and it's a plywood made out of soya glue, 521 00:40:53,862 --> 00:40:58,000 no particle board, no strand board, no resin, no formaldehyde. 522 00:40:59,160 --> 00:41:00,605 This is putrid. 523 00:41:00,640 --> 00:41:03,720 I had this open almost a year and it still smells. 524 00:41:03,755 --> 00:41:07,440 This smell... Come over here. 525 00:41:11,480 --> 00:41:13,605 It's bad, it's very, very bad. 526 00:41:13,640 --> 00:41:15,600 I can't smell anything though. 527 00:41:16,720 --> 00:41:18,520 You can't? Get over here. 528 00:41:18,555 --> 00:41:20,320 But it doesn't affect me. 529 00:41:20,355 --> 00:41:22,885 Really? Why is that? 530 00:41:22,920 --> 00:41:26,445 Um, probably cos you're not sick like I am. 531 00:41:26,480 --> 00:41:31,840 You know you still are working at 100% so you're able to de-tox it out. 532 00:41:34,200 --> 00:41:37,920 Despite the heartfelt testimony of Nancy and thousands like her, 533 00:41:37,955 --> 00:41:41,937 the medical establishment continues to doubt the bold claims 534 00:41:41,972 --> 00:41:45,920 of MCS sufferers and is sceptical about the wide variety 535 00:41:45,955 --> 00:41:48,360 and vagueness of symptoms. 536 00:41:51,480 --> 00:41:55,280 As a result, the American Medical Association has not yet granted 537 00:41:55,315 --> 00:41:59,280 the condition the status of a genuine medical disorder. 538 00:42:02,120 --> 00:42:06,645 Many doctors believe that MCS sufferers may not be allergic at all 539 00:42:06,680 --> 00:42:12,520 but like millions of others might be reacting to something else entirely. 540 00:42:18,160 --> 00:42:20,325 Across the developed world today, 541 00:42:20,360 --> 00:42:23,525 almost every other person seems to be allergic to something. 542 00:42:23,560 --> 00:42:27,000 The symptoms are that you just want to scratch when you get into bed. 543 00:42:27,035 --> 00:42:29,645 I would just sneeze and sneeze non-stop. 544 00:42:29,680 --> 00:42:33,920 I end up vomiting like severe vomit for about 24 hours to 48 hours. 545 00:42:35,640 --> 00:42:39,480 But are all these symptoms really allergic reactions? 546 00:42:39,515 --> 00:42:42,037 I sneeze a lot and I get colds. 547 00:42:42,072 --> 00:42:44,525 I have eczema. A scratchy throat. 548 00:42:44,560 --> 00:42:47,720 Rashes. I have to go hospital because I turn red. 549 00:42:48,760 --> 00:42:51,245 While symptoms may sound genuine enough, 550 00:42:51,280 --> 00:42:54,280 psychologist Rebecca Knibb believes that not everyone 551 00:42:54,315 --> 00:42:57,280 who feels themselves to be allergic actually are. 552 00:42:59,560 --> 00:43:03,680 Up to about 35% of people worldwide, really 553 00:43:03,715 --> 00:43:05,645 across most westernised countries, 554 00:43:05,680 --> 00:43:08,820 think they react to food whereas bring them into clinic, 555 00:43:08,855 --> 00:43:11,960 maybe only one to two percent of the adult population react 556 00:43:11,995 --> 00:43:14,560 and maybe five to six percent of children. 557 00:43:16,960 --> 00:43:20,920 The huge discrepancy between what people believe they are allergic to 558 00:43:20,955 --> 00:43:24,120 and what they test positive for, may be because some people 559 00:43:24,155 --> 00:43:27,805 are confusing allergies with food intolerances. 560 00:43:27,840 --> 00:43:31,040 The general public don't tend to understand the difference 561 00:43:31,075 --> 00:43:32,885 between allergy and intolerance. 562 00:43:32,920 --> 00:43:36,320 An allergy is where you have an actual immune mediated reaction 563 00:43:36,355 --> 00:43:39,277 and these reactions tend to be quite quick reactions. 564 00:43:39,312 --> 00:43:42,165 They can happen very rapidly once you've eaten a food 565 00:43:42,200 --> 00:43:45,760 or even come into contact with a food that you might be allergic to. 566 00:43:45,795 --> 00:43:49,285 Food intolerances are different. They don't involve the immune system. 567 00:43:49,320 --> 00:43:53,280 There's a much longer time between eating the food and getting a reaction. 568 00:43:53,315 --> 00:43:56,725 It can be six, eight hours before you actually react. 569 00:43:56,760 --> 00:43:59,840 But for others, there may be a completely different reason 570 00:43:59,875 --> 00:44:02,325 why they believe themselves to be allergic. 571 00:44:02,360 --> 00:44:08,200 If you actually are extremely worried and anxious that you're going to get a particular type of symptoms, 572 00:44:08,235 --> 00:44:12,400 then that fear and that stress may possibly trigger those symptoms. 573 00:44:12,435 --> 00:44:16,165 So, we've seen this in studies where stress has triggered 574 00:44:16,200 --> 00:44:19,640 histamine release for example and histamine is one of the things 575 00:44:19,675 --> 00:44:22,400 that's released when you have an allergic reaction. 576 00:44:22,435 --> 00:44:24,725 So, again, you are getting actual symptoms, 577 00:44:24,760 --> 00:44:27,820 it's not all in the mind but it might be that it's more 578 00:44:27,855 --> 00:44:30,880 psychological factors that are causing those symptoms 579 00:44:30,915 --> 00:44:33,560 rather than physiological factors. 580 00:44:37,000 --> 00:44:39,445 Records of the global increase in allergies 581 00:44:39,480 --> 00:44:43,100 are based on confirmed results but when it comes to allergies, 582 00:44:43,135 --> 00:44:46,720 it's crucial not to underestimate the power of psychology. 583 00:44:55,520 --> 00:44:58,840 Around the globe, scientists have been gradually uncovering 584 00:44:58,875 --> 00:45:01,560 the complex web of causes of the allergy epidemic. 585 00:45:05,000 --> 00:45:08,920 But to date, all these incremental advances offer little hope to 586 00:45:08,955 --> 00:45:11,005 the millions of sufferers affected, 587 00:45:11,040 --> 00:45:14,200 sufferers who are holding out hope for an effective cure. 588 00:45:24,400 --> 00:45:27,760 I can't remember exactly what happened because I was quite young 589 00:45:27,795 --> 00:45:29,725 but I remember bits of what happened. 590 00:45:29,760 --> 00:45:36,640 When the dog touched me I felt very sleepy, just wanted to sleep. 591 00:45:37,760 --> 00:45:42,720 Within seconds, Danny was crying, saying he felt strange 592 00:45:42,755 --> 00:45:44,565 and his face swelled. 593 00:45:44,600 --> 00:45:47,320 There was like this white jelly inside his eyes 594 00:45:47,355 --> 00:45:51,925 and he was totally unresponsive. 595 00:45:51,960 --> 00:45:56,120 Eight year old Danny Pearse has one of the most severe dog allergies in Britain. 596 00:45:56,155 --> 00:45:59,920 In the past, he's been hospitalised with anaphylactic shock - 597 00:45:59,955 --> 00:46:03,080 the most extreme form of allergic reaction. 598 00:46:04,880 --> 00:46:07,640 When a dog comes along he will just run across the road 599 00:46:07,675 --> 00:46:10,437 to the other side of the road to avoid the dog. 600 00:46:10,472 --> 00:46:13,165 He doesn't see danger - when he just sees the dog. 601 00:46:13,200 --> 00:46:17,760 He just goes to pieces, he grabs your hand and he is frightened to death. 602 00:46:19,240 --> 00:46:23,205 They worry about me when I go out to play because they 603 00:46:23,240 --> 00:46:28,000 dunno what might be happening and what I might be up to outside. 604 00:46:34,400 --> 00:46:38,160 Danny and his family are hoping that soon their fears may become a thing 605 00:46:38,195 --> 00:46:43,157 of the past. They have agreed to try an experimental new treatment, 606 00:46:43,192 --> 00:46:48,120 that, if successful, may cure Danny of his potentially fatal allergy. 607 00:46:49,480 --> 00:46:52,845 Every day for the last year, Danny has received tiny 608 00:46:52,880 --> 00:46:57,200 but gradually increasing doses of dog allergen under his tongue. 609 00:46:57,235 --> 00:47:01,485 In Danny's case, we started with a really miniscule amount of dog 610 00:47:01,520 --> 00:47:05,800 allergen, yet still he had a very clear reaction the first time he was exposed to it. 611 00:47:05,835 --> 00:47:10,120 So we had to build him up extremely slowly, allowing his body to let us 612 00:47:10,155 --> 00:47:13,000 know when it was tolerating it, when we were pushing too far. 613 00:47:14,400 --> 00:47:17,440 Today, Danny will be exposed to the same species of dog 614 00:47:17,475 --> 00:47:19,480 that he first reacted to. 615 00:47:21,520 --> 00:47:24,360 I'm obviously feeling a little apprehensive. 616 00:47:24,395 --> 00:47:26,565 This is breaking new ground for us. 617 00:47:26,600 --> 00:47:31,400 It's the first real test of the treatment that we've never used in this way before. 618 00:47:33,880 --> 00:47:37,525 It is very scary, because potentially any time things 619 00:47:37,560 --> 00:47:42,060 can change, but we've just gotta do it, we got to go with it now. 620 00:47:42,095 --> 00:47:46,560 At every stage of the test, Danny's blood pressure, temperature, 621 00:47:46,595 --> 00:47:49,537 heart rate and oxygen levels will be monitored. 622 00:47:49,572 --> 00:47:52,480 Blood will also be taken to check for any sign of 623 00:47:52,515 --> 00:47:53,920 an allergic reaction. 624 00:47:55,760 --> 00:47:59,480 Since Danny has had such severe reactions in the past, 625 00:47:59,515 --> 00:48:01,040 he will be exposed gradually. 626 00:48:03,400 --> 00:48:07,800 After firstly being exposed to the room where the dog has been, 627 00:48:07,835 --> 00:48:11,640 Danny must then sit next to the dog without touching it. 628 00:48:24,840 --> 00:48:27,320 Feeling OK? Yeah, feel fine. Good OK, fine. 629 00:48:32,080 --> 00:48:33,645 Having suffered no reaction, 630 00:48:33,680 --> 00:48:36,320 Danny will now have full exposure to the dog. 631 00:48:38,040 --> 00:48:40,640 The last time this happened, he fell unconscious. 632 00:48:43,960 --> 00:48:47,120 Yeah, I just want him to get him on the floor. 633 00:48:48,280 --> 00:48:50,285 I'm a bit worried he's going to bite me. 634 00:48:50,320 --> 00:48:53,440 He definitely won't bite you, he's really soft, look. 635 00:48:53,475 --> 00:48:56,560 He is nervous because, are you feeling a bit nervous? 636 00:49:03,640 --> 00:49:05,800 HE LAUGHS 637 00:49:06,720 --> 00:49:09,685 Ready, steady, go. 638 00:49:09,720 --> 00:49:12,405 That's it, that's it! Well done! Yes yes yes! 639 00:49:12,440 --> 00:49:15,765 Fantastic, you got it right to the top. Well done. 640 00:49:15,800 --> 00:49:19,280 I'm just glad that today's over and done with. I think the kind 641 00:49:19,315 --> 00:49:21,817 of stress levels can go down a bit now because... 642 00:49:21,852 --> 00:49:24,246 it feels it's almost surreal as well, isn't it? 643 00:49:24,281 --> 00:49:26,605 It feels surreal in this room with this dog. 644 00:49:26,640 --> 00:49:30,480 We've had no reaction whatsoever. It just demonstrates how effective the 645 00:49:30,515 --> 00:49:34,040 treatment's been, I think, doesn't it? OK? You all right? 646 00:49:34,075 --> 00:49:35,960 You are quiet, it's not like you. 647 00:49:40,200 --> 00:49:44,280 30 minutes after touching the dog, Danny starts to feel unwell. 648 00:49:46,600 --> 00:49:50,160 Minutes afterwards, Danny is violently ill. 649 00:49:52,440 --> 00:49:55,320 Doctor Fox and his team cannot take any chances. 650 00:49:57,200 --> 00:50:00,920 It's not completely clear whether this is an allergic reaction or not. 651 00:50:00,955 --> 00:50:03,725 His heart rate actually went down which was something 652 00:50:03,760 --> 00:50:07,680 we wouldn't expect if he's having an allergic reaction - it would go up. 653 00:50:07,715 --> 00:50:11,760 To get a better understanding of that, we've done some blood tests. 654 00:50:11,795 --> 00:50:14,560 The blood tests will take two or three days 655 00:50:14,595 --> 00:50:16,725 before we get the results back. 656 00:50:16,760 --> 00:50:20,645 Immuno-therapy is certainly tried and tested in pollen allergies 657 00:50:20,680 --> 00:50:25,000 but we have far less experience at using it in these sorts of reactions to animals. 658 00:50:26,200 --> 00:50:31,045 Rather embarrassingly for a treatment that's been around in active use for 659 00:50:31,080 --> 00:50:35,600 over a hundred years, we have a very poor understanding really of exactly how it works. 660 00:50:37,480 --> 00:50:40,880 For those doctors on the front line of treating allergies, these 661 00:50:40,915 --> 00:50:44,165 gaps in their knowledge are taking them back to basics. 662 00:50:44,200 --> 00:50:47,840 They're having to search for answers through trial and error. 663 00:50:53,200 --> 00:50:56,360 Dr Gideon Lack is an allergy specialist, looking at 664 00:50:56,395 --> 00:50:58,485 the moment that allergies begin. 665 00:50:58,520 --> 00:51:02,640 Allergies tend to develop sometime during the first year of life. 666 00:51:02,675 --> 00:51:04,925 Babies are not born allergic, 667 00:51:04,960 --> 00:51:09,640 they're born with a clean slate as far as the immune system goes, 668 00:51:09,675 --> 00:51:12,680 and their immune system has to become educated 669 00:51:12,715 --> 00:51:14,645 and has to develop over time. 670 00:51:14,680 --> 00:51:18,840 Sometimes the learning goes wrong and they become allergic to the food. 671 00:51:22,120 --> 00:51:25,280 Traditional medical thinking has been that because of this, 672 00:51:25,315 --> 00:51:26,965 avoidance is the best strategy. 673 00:51:27,000 --> 00:51:31,040 For instance women with a history of allergies have been advised to avoid 674 00:51:31,075 --> 00:51:34,597 eating peanuts while pregnant and to avoid feeding them to 675 00:51:34,632 --> 00:51:38,120 their young children in case they too develop an allergy, 676 00:51:38,155 --> 00:51:42,085 but even the evidence for this is shaky. 677 00:51:42,120 --> 00:51:45,440 What is interesting is there are many countries where peanuts 678 00:51:45,475 --> 00:51:49,525 appear to be eaten at a much earlier age 679 00:51:49,560 --> 00:51:52,440 and children nevertheless don't have peanut allergy. 680 00:51:54,400 --> 00:51:59,080 I used to sit in clinic a bit like an idiot because mothers, 681 00:51:59,115 --> 00:52:01,605 fathers would ask me, "What should I do? 682 00:52:01,640 --> 00:52:04,840 "I'm pregnant, should I give peanuts to my baby or not?" 683 00:52:04,875 --> 00:52:08,040 And I would tell them, "Look, we really don't have a clue. " 684 00:52:08,075 --> 00:52:11,125 It's a simple question - there's a simple answer. 685 00:52:11,160 --> 00:52:15,000 We just don't know it and we decided that it was really right to try and 686 00:52:15,035 --> 00:52:17,720 do something about it and find out. 687 00:52:19,240 --> 00:52:24,080 In a groundbreaking study, hundreds of babies are being fed peanuts to see if they 688 00:52:24,115 --> 00:52:28,720 really are more likely to develop an allergy compared to those who avoid. 689 00:52:28,755 --> 00:52:31,797 Im quite nervous, I am quite nervous. 690 00:52:31,832 --> 00:52:34,805 Why is that? I don't know, really. 691 00:52:34,840 --> 00:52:38,560 I think it's just the hype of the reaction that could go with it. 692 00:52:42,360 --> 00:52:47,000 The theory for introducing peanuts really is for the body's immune 693 00:52:47,035 --> 00:52:49,085 system to become tolerant of foods. 694 00:52:49,120 --> 00:52:52,840 It has to be exposed to the foods and recognise the foods 695 00:52:52,875 --> 00:52:55,240 as a friend rather than a foe. 696 00:52:55,275 --> 00:52:57,005 Is that a new taste? 697 00:52:57,040 --> 00:52:59,960 Is that something a bit different? 698 00:53:01,880 --> 00:53:05,120 It will take another four years for Professor Lack and his team 699 00:53:05,155 --> 00:53:07,480 to establish the answer to his simple question. 700 00:53:09,160 --> 00:53:13,420 But at least the immuno-therapy for Danny's dog allergy has had 701 00:53:13,455 --> 00:53:17,827 concrete results. His blood tests and a further dog challenge 702 00:53:17,862 --> 00:53:21,951 have confirmed that Danny's episode was not an allergic reaction. 703 00:53:21,986 --> 00:53:26,040 It was most probably brought on by the stress of the situation. 704 00:53:26,075 --> 00:53:27,485 Is he your new friend then? 705 00:53:27,520 --> 00:53:30,800 Pardon? Is he your new friend? Yeah. I think so, new best friend. 706 00:53:30,835 --> 00:53:34,257 Fortunately, together with further tests we were able to do, 707 00:53:34,292 --> 00:53:37,680 it was very clear that that reaction wasn't an allergic reaction 708 00:53:37,715 --> 00:53:40,405 of any sorts, but to be absolutely sure we brought 709 00:53:40,440 --> 00:53:44,285 Danny back a couple of weeks later, and repeated the entire exercise. 710 00:53:44,320 --> 00:53:48,205 The only difference we made is that we made the whole thing much lower key. 711 00:53:48,240 --> 00:53:54,560 We didn't have any television cameras there and the whole thing went off extremely well. 712 00:53:54,595 --> 00:53:58,277 At the end of the day, just over a year ago, he wouldn't have been 713 00:53:58,312 --> 00:54:01,960 able to go in the room with a dog, let alone do what he's doing today. 714 00:54:01,995 --> 00:54:03,925 We never dreamt for a minute 715 00:54:03,960 --> 00:54:08,520 that it'd be as successful as it been within the first 12 months. 716 00:54:08,555 --> 00:54:10,885 It's been amazing - absolutely amazing. 717 00:54:10,920 --> 00:54:14,325 I think he's going to appreciate over the years how hard it's been, 718 00:54:14,360 --> 00:54:19,880 and stressful and what you've been through, whereas now you can sort of relax more, a lot more. 719 00:54:19,915 --> 00:54:24,205 It's been life-changing for the family and for Danny. 720 00:54:24,240 --> 00:54:28,685 I didn't think it would ever be like that, the dog on the swing. 721 00:54:28,720 --> 00:54:35,280 When I went to Cardiff Bay with the school and there was this tree that 722 00:54:35,315 --> 00:54:37,005 you can make a wish on and I wished 723 00:54:37,040 --> 00:54:40,560 that one day I'd be able to stroke dogs and it's come true. 724 00:54:45,880 --> 00:54:49,565 While immuno-therapy has the potential to transform lives 725 00:54:49,600 --> 00:54:53,040 of patients like Danny, with little real scientific understanding 726 00:54:53,075 --> 00:54:57,177 of how the treatment works, it is not appropriate for everyone. 727 00:54:57,212 --> 00:55:01,280 An effective mass treatment for allergies is still a long way off. 728 00:55:04,200 --> 00:55:07,960 In spite of decades of research and many breakthroughs, the allergy 729 00:55:07,995 --> 00:55:10,720 epidemic is not showing any signs of slowing down. 730 00:55:13,440 --> 00:55:16,525 Even as science uncovers more about the causes, 731 00:55:16,560 --> 00:55:20,160 across the globe, more and more people are succumbing to allergies. 732 00:55:23,560 --> 00:55:28,120 What is clear is that the solution to the crisis does not lie in one place alone. 733 00:55:28,155 --> 00:55:32,797 From the Caribbean to California, Texas to Tristan da Cunha, 734 00:55:32,832 --> 00:55:37,440 LA to London, there is no one answer to the allergy puzzle. 735 00:55:37,475 --> 00:55:40,325 The most important factor may well lie 736 00:55:40,360 --> 00:55:42,765 in how all the different pieces fit together. 737 00:55:42,800 --> 00:55:46,480 Both allergy and asthma are not caused by a single factor. 738 00:55:46,515 --> 00:55:48,325 In fact, so for many factors, 739 00:55:48,360 --> 00:55:51,760 we don't even know what they are and how many they are. 740 00:55:53,560 --> 00:55:55,565 It's absolutely frightening. 741 00:55:55,600 --> 00:55:59,560 If this progresses, without any stop... 742 00:55:59,595 --> 00:56:01,405 just a question of time. 743 00:56:01,440 --> 00:56:04,080 Virtually everybody's going to be asthmatic. 744 00:56:06,240 --> 00:56:10,085 Over the past 50 years, rapid technological advance and rising 745 00:56:10,120 --> 00:56:15,040 standards of living have transformed our lives beyond all recognition. 746 00:56:17,640 --> 00:56:20,960 But this frenetic pace of change is exposing more and more 747 00:56:20,995 --> 00:56:23,680 genetic vulnerabilities, hidden in the past. 748 00:56:29,280 --> 00:56:33,445 Clearly we are exposed to toxins and a level of toxins 749 00:56:33,480 --> 00:56:37,400 that we've never been exposed to before, at least in evolutionary time. 750 00:56:37,435 --> 00:56:39,885 So in some ways we are very 751 00:56:39,920 --> 00:56:44,040 genetically and evolutionarily mismatched to this environment. 752 00:56:46,240 --> 00:56:51,360 We have changed the world around us, the food we eat, the air we breathe. 753 00:56:54,160 --> 00:56:57,600 We have successfully eradicated the infections and diseases 754 00:56:57,635 --> 00:57:00,057 that plagued previous generations. 755 00:57:00,092 --> 00:57:02,445 But in the process of modernising 756 00:57:02,480 --> 00:57:06,560 our world, we may have created a different plague altogether. 757 00:57:09,960 --> 00:57:14,200 Our immune system, our genetics, our make-up has actually evolved 758 00:57:14,235 --> 00:57:17,237 over hundreds of thousands and millions of years, 759 00:57:17,272 --> 00:57:20,736 whereas the changes in lifestyle are very sudden. 760 00:57:20,771 --> 00:57:24,200 So a 100,000 years ago, our ancestors would have been 761 00:57:24,235 --> 00:57:27,085 walking around in fields naked. 762 00:57:27,120 --> 00:57:30,580 They would be infested with parasites, their food would 763 00:57:30,615 --> 00:57:34,040 be often raw or uncooked. Today, everything has changed. 764 00:57:39,800 --> 00:57:43,725 This convergence, if you will, of our genes, 765 00:57:43,760 --> 00:57:47,720 various environmental factors, rapid changes in the domestic environment, 766 00:57:47,755 --> 00:57:53,000 changes in lifestyle due to rapid modernisation, all of the cars on 767 00:57:53,035 --> 00:57:56,480 the streets and the pollution that comes from these cars, 768 00:57:56,515 --> 00:57:59,805 it's sort of this perfect storm, if you will. 769 00:57:59,840 --> 00:58:04,260 All of these parts coming together to create the situation 770 00:58:04,295 --> 00:58:08,680 where there's seemingly no end to how far this will go. 771 00:58:26,480 --> 00:58:30,440 Subtitles by Red Bee Media Ltd 772 00:58:30,475 --> 00:58:34,400 E- mail subtitling@bbc. co. uk